CN110637419A

CN110637419A - CSI-RS configuration for partial band retuning

Info

Publication number: CN110637419A
Application number: CN201880032016.7A
Authority: CN
Inventors: 张煜; 陈万士
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2017-05-17
Filing date: 2018-04-20
Publication date: 2019-12-31
Anticipated expiration: 2038-04-20
Also published as: WO2018210098A1; EP3625897B1; US11689319B2; EP3625897A1; US20200153552A1; WO2018209596A1; CN110637419B; EP3625897A4

Abstract

Methods, systems, and devices for wireless communication are described. A User Equipment (UE) may receive a message indicating a set of possible channel state information reference signal (CSI-RS) configurations for each or multiple partial bands. The UE may further receive Downlink Control Information (DCI) from the base station, which may indicate a set of downlink resources associated with the first fractional frequency band. The UE may select a first CSI-RS configuration from a set of possible CSI-RS configurations for a first fractional frequency band based on the DCI, and when the base station transmits CSI-RS, the UE may obtain CSI-RS measurements on the first fractional frequency band during a set of downlink resources using the selected first CSI-RS configuration.

Description

CSI-RS configuration for partial band retuning

Cross-referencing

This patent application claims priority from international patent application No. pct/CN2017/084710 entitled "CSI-RS CONFIGURATION FOR PARTIAL BAND tuning" filed by ZHANG et al on 2017, 5, month 17, which is assigned to the assignee of the present application and is incorporated herein by reference in its entirety.

Background

The following relates generally to wireless communications, and more particularly to CSI-RS configuration for partial band retuning. .

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be able to support communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems (e.g., Long Term Evolution (LTE) systems, or New Radio (NR) systems). A wireless multiple-access communication system may include several base stations or access network nodes, each supporting communication for multiple communication devices simultaneously, which may otherwise be referred to as User Equipment (UE).

A UE operating in a wireless communication system may support a system bandwidth. In some cases, the UE may be configured to communicate over the entire system bandwidth (e.g., 20MHz, 100MHz, etc.). Alternatively, the UE may be configured to communicate via a narrowband or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the system bandwidth. In some cases, the UE may be dynamically configured by the base station to switch or retune to a different fractional frequency band.

Channel state information reference signals (CSI-RS) may be transmitted by the base station according to a resource pattern. The UE may measure the CSI-RS transmission to obtain channel state information, which may be relayed back to the base station. The CSI-RS transmission mode is conventionally configured at the Radio Resource Control (RRC) layer (e.g., during establishment or reconfiguration of a connection between a base station and a UE). Current wireless communication systems are not adequate for partial bands for CSI-RS transmission.

SUMMARY

Various described techniques relate to improved methods, systems, devices, or apparatus that support channel state information reference signal (CSI-RS) configuration for partial band retuning. A User Equipment (UE) may receive a message indicating a set of possible CSI-RS configurations for each or multiple partial bands. The UE may further receive Downlink Control Information (DCI) from the base station, which may indicate a set of downlink resources associated with the first fractional frequency band. The UE may select a first CSI-RS configuration from a set of possible CSI-RS configurations for a first fractional frequency band based on the DCI, and when the base station transmits CSI-RS, the UE may use the selected first CSI-RS configuration to obtain CSI-RS measurements on the first fractional frequency band during the set of downlink resources.

A method of wireless communication is described. The method can comprise the following steps: the method includes receiving, from a base station, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, selecting, based at least in part on the DCI, a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and obtaining CSI-RS measurements on the first partial band during the set of downlink resources using the selected first CSI-RS configuration.

An apparatus for wireless communication is described. The apparatus may include: the apparatus generally includes means for receiving, from a base station, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of a UE, means for receiving, from the base station, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, means for selecting, based at least in part on the DCI, a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and means for using the selected first CSI-RS configuration to obtain CSI-RS measurements on the first partial band during the set of downlink resources.

Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: the method includes receiving, from a base station, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, selecting, based at least in part on the DCI, a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and obtaining CSI-RS measurements on the first partial band during the set of downlink resources using the selected first CSI-RS configuration.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: the method includes receiving, from a base station, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, selecting, based at least in part on the DCI, a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and obtaining CSI-RS measurements on the first partial band during the set of downlink resources using the selected first CSI-RS configuration.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: retuning a receiver of the UE from the second fractional frequency band to the first fractional frequency band based at least in part on the received DCI.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: selecting a CSI-RS configuration from a set of possible CSI-RS configurations for the first fractional frequency band based at least in part on periodic CSI-RS information in the received message. In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described above, the received message may be a Radio Resource Control (RRC) message.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: selecting a CSI-RS configuration from a set of possible CSI-RS configurations for the first partial band based at least in part on semi-persistent CSI-RS information in the received message.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, the received message may be a Medium Access Control (MAC) layer message. In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, selecting a CSI-RS configuration comprises: an indication of a first CSI-RS configuration is received in DCI.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: transmitting a Channel State Information (CSI) report to a base station based at least in part on a CSI-RS measurement on a first partial band.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, at least one of the set of possible CSI-RS configurations corresponds to a zero-power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero-power (NZP) CSI-RS.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, the set of possible CSI-RS configurations includes at least two subsets of possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics.

In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration. In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, at least one of the subset of possible CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

A method of wireless communication is described. The method can comprise the following steps: the apparatus generally includes means for transmitting, to a UE, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE, means for transmitting, to the UE, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, means for selecting, based at least in part on the set of downlink resources, a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and means for performing CSI-RS transmission during the set of downlink resources in accordance with the determined CSI-RS configuration.

An apparatus for wireless communication is described. The apparatus may include: the apparatus generally includes means for transmitting, to a UE, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE, means for transmitting, to the UE, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, means for selecting, based at least in part on the set of downlink resources, a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and means for performing CSI-RS transmission during the set of downlink resources in accordance with the determined CSI-RS configuration.

Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: the apparatus generally includes means for transmitting, to a UE, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE, means for transmitting, to the UE, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, means for selecting, based at least in part on the set of downlink resources, a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and means for performing CSI-RS transmission during the set of downlink resources in accordance with the determined CSI-RS configuration.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: the apparatus generally includes means for transmitting, to a UE, a message indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE, means for transmitting, to the UE, DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands, means for selecting, based at least in part on the set of downlink resources, a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band, and means for performing CSI-RS transmission during the set of downlink resources in accordance with the determined CSI-RS configuration.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: transmitting instructions to retune a receiver of the UE from the second fractional frequency band to the first fractional frequency band based via the DCI.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: selecting a CSI-RS configuration from a set of possible CSI-RS configurations for the first fractional frequency band based at least in part on periodic CSI-RS information in the transmitted message.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, the transmitted message may be an RRC message. Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: selecting a CSI-RS configuration from a set of possible CSI-RS configurations for the first partial band based at least in part on semi-persistent CSI-RS information in the transmitted message.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, the transmitted message may be a MAC layer message. In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, selecting a CSI-RS configuration comprises: transmitting an indication of a first CSI-RS configuration in the DCI.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: receiving a CSI report from the UE according to the determined CSI-RS configuration based at least in part on the performed CSI-RS transmission.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, at least one of the set of possible CSI-RS configurations corresponds to a ZP CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a NZP CSI-RS.

In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, the set of possible CSI-RS configurations includes at least two subsets of possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics. In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration.

In some examples of the above-described methods, apparatuses (devices), and non-transitory computer-readable media, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described above, at least one of the subset of possible CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

A method of wireless communication is described. The method can comprise the following steps: the method generally includes receiving, from a base station, a CSI-RS configuration associated with a first fractional frequency band within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a second fractional frequency band within the total configured bandwidth of the UE, and transmitting one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first fractional frequency band and the second fractional frequency band.

An apparatus for wireless communication is described. The apparatus may include: the apparatus generally includes means for receiving, from a base station, a CSI-RS configuration associated with a first partial band within a total configured bandwidth of a UE, means for receiving, from the base station, DCI indicating a set of downlink resources associated with a second partial band within the total configured bandwidth of the UE, and means for transmitting one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first partial band and the second partial band.

Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: the method generally includes receiving, from a base station, a CSI-RS configuration associated with a first fractional frequency band within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a second fractional frequency band within the total configured bandwidth of the UE, and transmitting one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first fractional frequency band and the second fractional frequency band.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: the method generally includes receiving, from a base station, a CSI-RS configuration associated with a first fractional frequency band within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a second fractional frequency band within the total configured bandwidth of the UE, and transmitting one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first fractional frequency band and the second fractional frequency band.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: some examples of the above-described methods, apparatuses (devices) and non-transitory computer-readable media may further include processes, features, means or instructions for: transmitting the error message based at least in part on the determination.

Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: a portion of the first fractional frequency band that overlaps the second fractional frequency band is determined. Some examples of the above-described methods, apparatus (devices), and non-transitory computer-readable media may further include processes, features, means, or instructions for: CSI-RS measurements are obtained over the portion of the first fractional frequency band that overlaps the second fractional frequency band.

Brief Description of Drawings

Fig. 1 illustrates an example of a system for wireless communication that supports a channel state information reference signal (CSI-RS) configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 2 illustrates an example of a wireless communication system supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 3 illustrates an example of a partial band retuning scenario supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 4 illustrates an example of a partial band retuning scenario supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 5 illustrates an example of a partial band retuning scenario supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 6 illustrates an example of a partial band retuning scenario supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 7 illustrates an example of a partial band retuning scenario supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 8 illustrates an example of CSI-RS configuration settings supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 9 illustrates an example of CSI-RS configuration settings supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 10 illustrates an example of a process flow supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 11-13 show block diagrams of devices supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 14 illustrates a block diagram of a system including a UE supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 15-17 show block diagrams of devices supporting CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 18 illustrates a block diagram of a system including a base station supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Fig. 19-21 illustrate methods of CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure.

Detailed Description

A User Equipment (UE) operating in a wireless communication system may have a system bandwidth. In some cases, the UE may be configured to communicate over the entire system bandwidth (e.g., 20MHz, 100MHz, etc.). Alternatively, the UE may be configured to communicate via a narrowband or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the system bandwidth. In some cases, the UE may be dynamically configured by the base station to switch or retune to a different fractional frequency band.

Channel state information reference signals (CSI-RS) may be transmitted by the base station according to a resource pattern. The UE may measure the CSI-RS transmission to obtain channel state information, which may be relayed back to the network. The CSI-RS transmission mode is conventionally configured on the Radio Resource Control (RRC) layer (e.g., during establishment and reconfiguration of a connection between a base station and a UE). Because these RRC communications occur much less frequently than the UE's resource grants, the CSI-RS configuration may not be reconfigured as frequently as changes in the location or bandwidth of the resources granted to the UE. In such cases, the UE may retune to a different fractional frequency band based on a grant in Downlink Control Information (DCI) received from the base station without receiving a new CSI-RS configuration in an RRC message. This situation may cause CSI-RS transmissions to occur outside of the partial band to which the UE has retuned, making it difficult or impossible for the UE to obtain accurate CSI-RS measurements. In such scenarios, it may be beneficial for the UE configuration or CSI-RS configuration to address partial band switching.

In one set of examples, the UE and the base station may use RRC messaging to set up or reconfigure the connection. As part of this process, the UE may receive an RRC message indicating a set of possible CSI-RS configurations for each partial band within the total configured bandwidth of the UE. Each possible CSI-RS configuration may include resource elements on which the UE may make CSI-RS measurements. The CSI-RS configuration may include one CSI-RS configuration per partial band or multiple CSI-RS configurations per partial band. Furthermore, the set of possible CSI-RS configurations may comprise a subset of CSI-RS configurations. Possible CSI-RS configurations may correspond to a particular type of CSI-RS (e.g., periodic, aperiodic, or semi-persistent CSI-RS information). Additionally or alternatively, possible CSI-RS configurations may be based on frequency locations within the total bandwidth, or fractional frequency bands within the total bandwidth. The UE may further receive a downlink grant from the base station, which may include DCI. The DCI may indicate a partial band retuning from the first partial band to the second partial band. In some cases, the DCI may further include: an indication of which of the possible CSI-RS configurations the UE should utilize for CSI-RS measurements.

In another set of examples, the UE may retune from the first fractional frequency band to the second fractional frequency band based on a downlink grant received from the base station. The UE may transmit an error message to the base station indicating a failure or inability to measure the CSI-RS if the first partial band and the second partial band do not overlap. If a portion of the first partial band overlaps a portion of the second partial band, the UE may determine an overlapping portion of the first partial band and the second partial band and perform a partial CSI-RS measurement on the overlapping portion. The UE may transmit the partial CSI-RS measurement to the base station. Aspects of the present disclosure are initially described in the context of a wireless communication system. Aspects of the present disclosure are further described in the context of partial band retuning scenarios and CSI-RS configuration settings. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to CSI-RS configurations for partial band retuning.

Fig. 1 illustrates an example of a wireless communication system 100 in accordance with various aspects of the present disclosure. The wireless communication system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE), LTE-advanced (LTE-a) network, or a New Radio (NR) network. In some cases, wireless communication system 100 may support enhanced broadband communications, ultra-reliable (i.e., mission critical) communications, low latency communications, and communications with low cost and low complexity devices. In some examples, the base station 105 may transmit a message including a set of possible CSI-RS configurations, and may also transmit DCI. The UE115 may determine the CSI-RS configuration to utilize based on the message, or the DCI, or both.

The base station 105 may communicate wirelessly with the UE115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. The communication links 125 shown in the wireless communication system 100 may include uplink transmissions from the UEs 115 to the base stations 105 or downlink transmissions from the base stations 105 to the UEs 115. Control information and data may be multiplexed on an uplink channel or a downlink according to various techniques. The control information and data may be multiplexed on the downlink channel using, for example, Time Division Multiplexing (TDM) techniques, Frequency Division Multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted during a Transmission Time Interval (TTI) of a downlink channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region and one or more UE-specific control regions).

UEs 115 may be dispersed throughout the wireless communication system 100, and each UE115 may be stationary or mobile. UE115 may also be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. The UE115 may also be a cellular phone, a Personal Digital Assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a Wireless Local Loop (WLL) station, an internet of things (IoT) device, an internet of everything (IoE) device, a Machine Type Communication (MTC) device, an appliance, an automobile, and so forth.

In some cases, the UE115 may also be able to communicate directly with other UEs (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs of the group of UEs 115 communicating with D2D may be within the geographic coverage area 110 of the cell. Other UEs 115 in such groups may be outside the geographic coverage area 110 of the cell or otherwise unable to receive transmissions from the base station 105. In some cases, groups of UEs 115 communicating via D2D may utilize a one-to-many (1: M) system, where each UE115 transmits to every other UE115 in the group. In some cases, the base station 105 facilitates scheduling of resources for D2D communication. In other cases, the D2D communication is performed independently of the base station 105.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide automated communication between machines, i.e., machine-to-machine (M2M) communication. M2M or MTC may refer to data communication techniques that allow devices to communicate with each other or with a base station without human intervention. For example, M2M or MTC may refer to communications from a device that integrates sensors or meters to measure or capture information and relay the information to a central server or application that may utilize the information or present the information to a human interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of a machine. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based business charging.

In some cases, MTC devices may operate at a reduced peak rate using half-duplex (one-way) communication. The MTC device may also be configured to enter a power saving "deep sleep" mode when not engaged in active communication. In some cases, MTC or IoT devices may be designed to support mission critical functions, and wireless communication systems may be configured to provide ultra-reliable communication for these functions.

Each base station 105 may communicate with the core network 130 and with each other. For example, the base station 105 may interface with the core network 130 over a backhaul link 132 (e.g., S1, etc.). The base stations 105 may communicate with each other over a backhaul link 134 (e.g., X2, etc.) either directly or indirectly (e.g., through the core network 130). The base station 105 may perform radio configuration and scheduling for communication with the UE115, or may operate under the control of a base station controller (not shown). In some examples, the base station 105 may be a macro cell, a small cell, a hot spot, and/or the like. The base station 105 may also be referred to as an evolved node B (eNB)105 or g B node (gNB).

The base station 105 may be connected to the core network 130 through an S1 interface. The core network may be an Evolved Packet Core (EPC) that may include at least one Mobility Management Entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). The MME may be a control node that handles signaling between the UE115 and the EPC. All user Internet Protocol (IP) packets may be communicated through the S-GW, which may itself be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to network operator IP services. Carrier IP services may include the internet, intranets, IP Multimedia Subsystem (IMS), and Packet Switched (PS) streaming services.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some network devices, such as base stations 105, may include subcomponents, such as access network entities, which may be examples of Access Node Controllers (ANCs). Each access network entity may communicate with several UEs 115 through several other access network transport entities, each of which may be an example of an intelligent radio head or a transmission/reception point (TRP). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., base station 105).

The wireless communication system 100 may operate using a frequency band from 700MHz to 2600MHz (2.6GHz) in the Ultra High Frequency (UHF) frequency region, but some networks, such as Wireless Local Area Networks (WLANs), may use frequencies up to 4 GHz. Since the wavelength is in the range from about 1 to 1 decimeter long, this region may also be referred to as a decimeter band. UHF waves may propagate primarily through the line of sight and may be blocked by building and environmental features. However, these waves may penetrate walls sufficiently to provide service to UEs 115 located indoors. UHF-wave transmission is characterized by a smaller antenna and shorter range (e.g., less than 100km) than transmission of smaller frequencies (and longer waves) using the High Frequency (HF) or Very High Frequency (VHF) portion of the spectrum. In some cases, wireless communication system 100 may also utilize the Extremely High Frequency (EHF) portion of the spectrum (e.g., from 30GHz to 300 GHz). Since the wavelength is in the range from about 1 millimeter to 1 centimeter long, this region may also be referred to as a millimeter band. Accordingly, the EHF antenna may be even smaller and more closely spaced than the UHF antenna. In some cases, this may facilitate the use of antenna arrays (e.g., for directional beamforming) within the UE 115. However, EHF transmissions may experience even greater atmospheric attenuation and shorter ranges than UHF transmissions.

As such, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE115 and the base station 105. Devices operating in the mmW or EHF bands may have multiple antennas to allow beamforming. That is, the base station 105 may use multiple antennas or antenna arrays for beamforming operations for directional communication with the UE 115. Beamforming, which may also be referred to as spatial filtering or directional transmission, is a signal processing technique that may be used at a transmitting party (e.g., base station 105) to shape and/or steer an overall antenna beam in the direction of an intended receiving party (e.g., UE 115). This may be achieved by combining elements in an antenna array in such a way that signals transmitted at a particular angle undergo constructive interference while other signals undergo destructive interference.

A multiple-input multiple-output (MIMO) wireless system uses a transmission scheme between a transmitting party (e.g., base station 105) and a receiving party (e.g., UE115), both equipped with multiple antennas. Portions of the wireless communication system 100 may use beamforming. For example, the base station 105 may have an antenna array with rows and columns of antenna ports that the base station 105 may use for beamforming in its communications with the UEs 115. The signal may be transmitted multiple times in different directions (e.g., each transmission may be beamformed differently). The mmW recipient (e.g., UE115) may attempt multiple beams (e.g., antenna sub-arrays) when receiving the synchronization signals.

In some cases, the antennas of a base station 105 or UE115 may be located within one or more antenna arrays that may support beamforming or MIMO operations. One or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with the base station 105 may be located at different geographic locations. The base station 105 may use multiple antennas or antenna arrays for beamforming operations for directional communication with the UEs 115.

In some cases, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication of the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. In some cases, the Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate on logical channels. The Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid arq (harq) to provide retransmission at the MAC layer, thereby improving link efficiency. In the control plane, a Radio Resource Control (RRC) protocol layer may provide for establishment, configuration, and maintenance of RRC connections of radio bearers supporting user plane data between the UE115 and the base station 105 or core network 130. At the Physical (PHY) layer, transport channels may be mapped to physical channels.

The time interval in LTE or NR may be a basic unit of time (which may be a sampling period T)_s1/30,720,000 seconds). The time resource may be 10ms (T) according to length_f＝307200T_s) May be organized by System Frame Numbers (SFNs) ranging from 0 to 1023. Each frame may include 101 ms subframes numbered from 0 to 9. The sub-frame may be further divided into two 0.5ms slots, where each slot contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix added before each symbol). Each symbol contains 2048 sample periods, excluding the cyclic prefix. In some casesIn this case, the subframe may be a minimum scheduling unit, also referred to as TTI. In other cases, the TTI may be shorter than a subframe or may be dynamically selected (e.g., in a short TTI burst or in a selected component carrier using a short TTI).

The resource element may include one symbol period and one subcarrier (e.g., 15KHz frequency range). A resource block may contain 12 consecutive subcarriers in the frequency domain and may contain 7 consecutive Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain (1 slot), or may contain 84 resource elements, for a normal cyclic prefix in each OFDM symbol. The number of bits carried by each resource element may depend on the modulation scheme (symbol configuration that may be selected during each symbol period). Thus, the more resource blocks the UE receives and the higher the modulation scheme, the higher the data rate may be.

The wireless communication system 100 may support operation on multiple cells or carriers, which is a feature that may be referred to as Carrier Aggregation (CA) or multi-carrier operation. The carriers may also be referred to as Component Carriers (CCs), layers, channels, and the like. The terms "carrier," "component carrier," "cell," and "channel" may be used interchangeably herein. The UE115 may be configured with multiple downlink CCs for carrier aggregation and one or more uplink CCs. Carrier aggregation may be used with Frequency Division Duplex (FDD) and Time Division Duplex (TDD) component carriers.

In some cases, the wireless communication system 100 may utilize an enhanced component carrier (eCC). An eCC may be characterized by one or more features, including: a wider bandwidth, a shorter symbol duration, a shorter TTI, and a modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (where more than one operator is allowed to use the spectrum). An eCC characterized by a wide bandwidth may include one or more segments that may be utilized by UEs 115 that are not capable of monitoring the entire bandwidth or preferentially use a limited bandwidth (e.g., to save power).

In some cases, the eCC may utilize a different symbol duration than other CCs, which may include using a reduced symbol duration compared to the symbol durations of the other CCs. The shorter symbol duration is associated with an increased subcarrier spacing. Devices utilizing an eCC, such as UE115 or base station 105, may transmit a wideband signal (e.g., 20, 40, 60, 80MHz, etc.) at a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may include one or more symbols. In some cases, the TTI duration (i.e., the number of symbols in a TTI) may be variable.

A shared radio frequency spectrum band may be utilized in an NR shared spectrum system. For example, NR shared spectrum may utilize any combination of licensed, shared, and unlicensed spectrum, among others. Flexibility in eCC symbol duration and subcarrier spacing may allow eCC to be used across multiple spectra. In some examples, NR sharing spectrum may increase spectrum utilization and spectrum efficiency, particularly through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ LTE licensed assisted access (LTE-LAA) or LTE unlicensed (LTE U) radio access technology or NR technology in unlicensed bands, such as the 5GHz industrial, scientific, and medical (ISM) band. When operating in the unlicensed radio frequency spectrum band, wireless devices, such as base stations 105 and UEs 115, may employ a Listen Before Talk (LBT) procedure to ensure that the channel is clear before transmitting data. In some cases, operation in the unlicensed band may be based on CA configuration in coordination with CCs operating in the licensed band. Operations in the unlicensed spectrum may include downlink transmissions, uplink transmissions, or both. Duplexing in unlicensed spectrum may be based on FDD, TDD, or a combination of both.

In some cases, the base station 105 may establish communication with the UE 115. The base station 105 may configure the CSI-RS transmission mode. The UE115 may be configured to operate on more than one fractional frequency band within the total bandwidth. In some examples, the base station 105 may transmit a resource grant to the UE115, which may indicate that the UE115 is to retune from the first partial band to the second partial band. However, the CSI-RS configuration may not be updated as often as retuning occurs. To address this scenario, the UE115 may be configured to make partial CSI-RS measurements or transmit an error message when CSI-RS resources are not available on the partial band. Additionally or alternatively, the base station 105 may include a set of possible CSI-RS configurations in the RRC message. The base station may receive a resource grant (which may include DCI) and utilize the RRC message or the DCI or both to select one of the CSI-RS configurations in the set of possible CSI-RS configurations. The UE115 may thus make accurate and complete CSI-RS measurements and transmit CSI-RS reports based on the CSI-RS measurements.

Fig. 2 illustrates an example of a wireless communication system 200 that supports a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100. The wireless communication system 200 may include a base station 105-a and a UE115-a, which may be examples of corresponding devices described with reference to fig. 1. A base station 105-a may communicate with one or more UEs 115-a within a geographic coverage area 205 via one or more bi-directional communication links 210. The UE115-a may have a system bandwidth and may be configured to communicate over the entire bandwidth (e.g., 20MHz, 100MHz, etc.). Alternatively, the UE115-a may be configured to communicate via a narrowband or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the system bandwidth. For example, UE115-a may be configured to communicate via a first fractional frequency band 215.

The base station 105-a may transmit the CSI-RS according to a resource pattern. The UE115-a may measure the CSI-RS transmission to obtain channel state information, which may be relayed back to the network. The CSI-RS pattern is conventionally configured at the Radio Resource Control (RRC) layer (e.g., during bi-directional communication link 210 setup and reconfiguration). However, the frequency of RRC communication may be much lower than the resource grant for UE 115-a. Thus, the CSI-RS configuration may not be reconfigured as frequently as the location or bandwidth of the resources granted to the UE. For example, UE115-a may be configured to communicate with base station 105-a via first fractional frequency band 215. Upon receiving the resource grant, the UE115-a may tune from the first partial band 215 to the second partial band 220. The second fractional frequency band 220 may have the same bandwidth as the first fractional frequency band 215, but may be located at a different frequency range in the frequency domain. Alternatively, the second fractional frequency band 220 may have a different bandwidth than the first fractional frequency band 215. For example, the first fractional frequency band 215 may be a 5MHz fractional frequency band and the second fractional frequency band 220 may be a 10MHz fractional frequency band.

In some examples, the UE115-a may receive a resource grant and retune from the first partial band 215 to the second partial band 220, but may not receive a new CSI-RS reconfiguration from the base station 105-a. Accordingly, the base station 105-a may transmit CSI-RS transmissions outside the second fractional frequency band 220 (e.g., in the first fractional frequency band 215). In such a case, the UE115-a may not be able to obtain accurate CSI-RS measurements.

In one set of examples, at the RRC layer, the base station 105-a may transmit an RRC message indicating a set of possible CSI-RS configurations for each partial band within the total configured bandwidth of the UE 115-a. Each possible CSI-RS configuration may identify resource elements on which the UE115-a may obtain CSI-RS measurements. The set of possible CSI-RS configurations may include one CSI-RS configuration per partial band, such that the UE115-a may determine which CSI-RS configuration to use based on the partial band to which the UE115-a retunes. In other examples, the set of possible CSI-RS configurations may include multiple CSI-RS configurations per partial band. For example, for each of the plurality of partial bands, the set of possible CSI-RS configurations may include some (4, 8, 12, etc.) CSI-RS configurations. Thus, the partial bands 215 and 220 may each correspond to 4 different CSI-RS configurations. UE115-a may receive DCI instructing it to retune from partial band 215 to partial band 220. The DCI may further include: the indication of which of the four CSI-RS configurations corresponding to the partial band 215 the UE115-a should utilize for CSI-RS measurements. For example, the DCI may include a two-bit indicator that indicates which of four possible CSI-RS configurations to use. In some examples, a Zero Power (ZP) CSI-RS and a non-zero power (NZP) CSI-RS may have different CSI-RS configurations for each partial band.

Furthermore, the set of possible CSI-RS configurations may be divided into subsets of CSI-RS configurations. Subsets of possible CSI-RS configurations may correspond to particular time domain characteristics of CSI-RS transmissions (e.g., periodic, aperiodic, or semi-persistent CSI-RS transmissions). For example, for each partial band, the set of possible CSI-RS configurations may include a subset of possible CSI-RS configurations for periodic CSI-RS (e.g., two configurations), a subset of possible CSI-RS configurations for aperiodic CSI-RS (e.g., two configurations), and a subset of possible CSI-RS configurations for semi-persistent CSI-RS configurations (e.g., three configurations). The periodic and semi-persistent CSI-RS configurations may be configured at the RRC level so that the UE115-a may determine which CSI-RS configuration to utilize based on RRC message reception. The aperiodic CSI-RS configuration may be indicated in the DCI.

Additionally or alternatively, possible CSI-RS configurations may be based on frequency locations within the total bandwidth, or fractional frequency bands within the total bandwidth. The UE115-a may further receive a downlink grant from the base station 105-a, which may include DCI. The DCI may indicate a partial band retuning from the first partial band 215 to the second partial band 220. In some cases, the DCI may further include: the indication of which of the possible CSI-RS configurations the UE115-a should utilize for CSI-RS measurements.

Additionally or alternatively, the UE115-a may retune from the first partial frequency band 215 to the second partial frequency band 220 based on a downlink grant received from the base station 105-a. If the first partial band 215 and the second partial band 220 do not overlap, the UE115-a may transmit an error message to the base station 105-a indicating that the UE115-a failed to measure the CSI-RS or was unable to measure the CSI-RS. If a portion of the first partial band 215 overlaps a portion of the second partial band 220, the UE115-a may determine an overlapping portion of the first partial band 215 and the second partial band 2220 and perform a partial CSI-RS measurement on the overlapping portion. In such a case, the UE115-a may transmit the partial CSI-RS measurement to the base station 105-a. Fig. 3 illustrates an example of a partial band retuning scenario 300 supporting a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the partial band retuning scenario 300 may implement aspects of the wireless communication system 100 of fig. 1 or the wireless communication system 200 of fig. 2. The partial band retuning scenario 300 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-2. In some cases, the UE115 may be configured with a total system bandwidth 305 (e.g., 20MHz, 100MHz, etc.). In some examples, the UE115 may be configured to communicate via a narrow band or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the overall system bandwidth 305. In some examples, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the overall system bandwidth 305.

For example, the UE115 may establish or reconfigure a connection with the base station 105 at the RRC layer. The UE115 may receive resources to communicate with the base station 105 via the fractional frequency band 310. Fractional frequency band 310 may be, for example, a 5MHz fractional frequency band. The UE115 may communicate with the base station 105 via the partial frequency band 315 for a certain duration determined by a grant from the base station 105. For example, the UE115 may communicate via the fractional frequency band 310 for three Transmission Time Intervals (TTIs) (e.g., slots, mini-slots, etc.). The grant of resources may include a gap period 320-a for retuning. That is, prior to the first time T1, the base station 105 may grant resources to the UE115 within a different fractional frequency band. During gap period 320-a, UE115 may retune to partial band 330. Fractional band 330 may be, for example, a 10MHz fractional band. UE115 may communicate with base station 105 via partial frequency band 330 for the indicated duration (e.g., 2 TTIs). The base station 105 may provide additional resource grants in different fractional frequency bands. During gap period 320-b, UE115 may retune from fractional frequency band 330 to fractional frequency band 335. At T2, UE115 may utilize resources within fractional frequency band 335 to communicate with base station 105.

However, the CSI-RS transmission mode may be configured at the RRC layer and the RRC communication may occur less frequently than the resource grants that trigger the UE115 to switch from one partial band to another at T1 and T2. The UE115 may receive an RRC message including a CSI-RS configuration. However, the received CSI-RS configuration may not configure CSI-RS transmissions for partial band 330 and partial band 335. In such a case, the UE115 may not be able to obtain an accurate CSI-RS configuration corresponding to the partial band 330 and the partial band 335. To address this scenario, the UE115 may be configured to send an error message or make partial measurements upon determining that the CSI-RS configuration does not correspond to the current partial band. Additionally or alternatively, the base station 105 may transmit a message to the UE115 during establishment or reconfiguration of the connection including a set of possible CSI-RS configurations. When the UE115 switches from the first partial band (e.g., partial band 310) to the second partial band (e.g., partial band 330), the UE115 may select one of the CSI-RS configurations in the set of possible CSI-RS configurations and thereby obtain accurate CSI-RS measurements.

Fig. 4 illustrates an example of a partial band retuning scenario 400 supporting a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the partial band retuning scenario 400 may implement aspects of the wireless communication system 100 or the wireless communication system 200. In some cases, partial band retuning scenario 400 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-3. In some cases, the UE115 may be configured with a total system bandwidth 405 (e.g., 20MHz, 100MHz, etc.).

In some examples, the UE115 may be configured to communicate via a narrowband or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the overall system bandwidth 405. In some examples, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the overall system bandwidth 405. For example, UE115 may be configured to operate on partial band 410 or partial band 415. Partial bands 410 and 415 may be the same bandwidth at different locations in the frequency domain. Alternatively, partial bands 410 and 415 may be partial bands having different bandwidths (e.g., 5MHz bandwidth, 10MHz bandwidth, or 20MHz bandwidth, etc.).

The base station 105 may transmit the CSI-RS according to a resource pattern. The CSI-RS pattern is conventionally configured at the RRC layer (e.g., during establishment and reconfiguration of a connection between the base station 105 and the UE 115). RRC messaging may configure the CSI-RS pattern for future transmissions. In some examples, the UE115 and the base station 105 may establish or reconfigure a connection, and the base station 105 may configure the UE115 to operate on the partial band 410. Additionally, the base station 105 may configure the CSI-RS pattern for future transmissions such that in the first TTI 420, the CSI-RS configuration 425 includes resources for CSI-RS transmissions on the partial band 410. During some future TTI 430, the CSI-RS configuration 435 may include additional resources for CSI-RS transmission on the partial band 410. However, RRC communication may occur much less frequently than resource grants for UE 115. Thus, the CSI-RS configuration may not be reconfigured as frequently as the location or bandwidth of resources granted to the UE 115. For example, the base station 105 may transmit a resource grant to the UE115 and in response, the UE115 may retune from the partial band 410 to the partial band 415. However, at TTI 430, CSI-RS configuration 435 is on partial band 410. Accordingly, the base station 105 may transmit CSI-RS on the fractional frequency band 410. In such cases, it may be difficult or impossible for the UE115 to obtain accurate CSI-RS measurements corresponding to the TTI 430. In such scenarios, it may be beneficial for the UE configuration or CSI-RS configuration to address the partial band switch.

To address this scenario, the UE115 may be configured to send an error message or make partial measurements upon determining that the CSI-RS configuration does not correspond to the current partial band. Additionally or alternatively, the base station 105 may transmit a message to the UE115 during establishment or reconfiguration of the connection including a set of possible CSI-RS configurations. When the UE115 switches from a first partial band (e.g., partial band 410) to a second partial band (e.g., partial band 415), the UE115 may select one of the CSI-RS configurations in the set of possible CSI-RS configurations and thereby obtain accurate CSI-RS measurements.

Fig. 5 illustrates an example of a partial band retuning scenario 500 that supports a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the partial band retuning scenario 500 may implement aspects of the wireless communication system 100. In some cases, the partial band retuning scenario 500 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-4. In some cases, the UE115 may be configured with a total system bandwidth 505 (e.g., 20MHz, 100MHz, etc.). In some examples, the UE115 may be configured to communicate via a narrow band or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the overall system bandwidth 505. In some examples, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the overall system bandwidth 505.

For example, UE115 may be configured to operate on partial band 510 or partial band 515. Partial bands 510 and 515 may be the same bandwidth at different locations in the frequency domain. Alternatively, partial bands 510 and 515 may be partial bands having different bandwidths (e.g., 5MHz bandwidth, 10MHz bandwidth, or 20MHz bandwidth, etc.). Each fractional band may include a range of Resource Blocks (RBs). For example, partial band 515 may include a RB range from RB M520 to RB N525. Partial band 510 may include a range of RBs from RBM + K _ 1530 to N + K _ 2535.

In some examples, the UE115 may receive an RRC message from the base station 105. The RRC message may include CSI-RS configuration information and an initial resource grant. The CSI-RS configuration information may indicate a CSI-RS configuration 540 on partial band 510 and a CSI-RS configuration 545 on partial band 515. The UE115 may receive a resource grant from the base station 105 and may dynamically retune from the fractional frequency band 510 to the fractional frequency band 515. However, the CSI-RS configuration may be updated less frequently than dynamic retuning occurs. Thus, the UE115 may be operating on the partial band 515 and may not be able to accurately obtain CSI-RS measurements.

In such examples, UE115 may determine whether fractional frequency band 510 overlaps with fractional frequency band 515. For example, UE115 may determine that RB M + K _ 1530 is greater than RB N525. In such examples, the UE115 may transmit an error message to the base station 105 indicating that measuring the CSI-RS failed or was not able to measure the CSI-RS. However, if fractional frequency band 510 does overlap with fractional frequency band 515, UE115 may be able to make some fractional measurements.

Additionally or alternatively, the base station 105 may transmit a message to the UE115 during establishment or reconfiguration of the connection including a set of possible CSI-RS configurations. The base station 105 may transmit a resource grant including DCI, which may initiate retuning at the UE 115. When the UE115 switches from a first partial band (e.g., partial band 510) to a second partial band (e.g., partial band 515), the UE115 may select one of the CSI-RS configurations from the set of possible CSI-RS configurations received during establishment or reconfiguration of the connection, and thereby obtain accurate CSI-RS measurements.

Fig. 6 illustrates an example of a partial band retuning scenario 600 supporting a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the partial band retuning scenario 600 may implement aspects of the wireless communication system 100. In some cases, partial band retuning scenario 600 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-5. In some cases, the UE115 may be configured with a total system bandwidth 505 (e.g., 20MHz, 100MHz, etc.). In some examples, the UE115 may be configured to communicate via a narrow band or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the overall system bandwidth 505. In some examples, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the overall system bandwidth 505.

For example, UE115 may be configured to operate on partial band 610 or partial band 615. The fractional frequency bands 610 and 615 may be the same bandwidth at different locations in the frequency domain. Alternatively, fractional frequency bands 610 and 615 may be fractional frequency bands having different bandwidths (e.g., 5MHz bandwidth, 10MHz bandwidth, or 20MHz bandwidth, etc.). Each fractional band may include a range of Resource Blocks (RBs). For example, fractional band 615 may include a range of RBs from RB M620 to RB N625. Fractional band 510 may include a range of RBs from RBM + K _ 1630 to N + K _ 2635.

In some examples, the UE115 may receive an RRC message from the base station 105. The RRC message may include CSI-RS configuration information and an initial resource grant. The CSI-RS configuration information may indicate a CSI-RS configuration 640 on the partial band 610 and a CSI-RS configuration 645 on the partial band 615. The UE115 may receive a resource grant from the base station 105 and may dynamically retune from the fractional frequency band 610 to the portion 615. However, the CSI-RS configuration may be updated less frequently than dynamic retuning occurs. Thus, the UE115 may be operating on the partial band 615 and may not be able to accurately obtain full CSI-RS measurements.

In such examples, UE115 may determine whether fractional frequency band 610 overlaps with fractional frequency band 615. For example, UE115 may determine that the maximum RB (RB N625) corresponding to fractional band 615 is greater than the minimum RB (RB M + K _ 1530) corresponding to fractional band 610. Accordingly, UE115 may determine an overlap 650 between partial band 610 and partial band 615. Thus, the UE115 may not be able to make a full CSI-RS measurement corresponding to the CSI-RS configuration 645 due to retuning to the partial band 615. However, upon determining that the partial band 610 overlaps the partial band 615, the UE115 may make CSI-RS measurements on the overlapping portion 650. However, in some examples, it may be beneficial to address the CSI-RS configuration so that the UE115 may make a complete CSI-RS measurement.

Additionally or alternatively, the base station 105 may transmit a message to the UE115 during establishment or reconfiguration of the connection including a set of possible CSI-RS configurations. The base station 105 may transmit a resource grant including DCI, which may initiate retuning at the UE 115. When the UE115 switches from a first partial band (e.g., partial band 610) to a second partial band (e.g., partial band 615), the UE115 may select one of the CSI-RSs in the set of possible CSI-RS configurations received during establishment or reconfiguration of the connection, and thereby obtain accurate CSI-RS measurements.

Fig. 7 illustrates an example of a partial band retuning scenario 700 supporting a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the partial band retuning scenario 700 may implement aspects of the wireless communication system 100. In some cases, partial band retuning scenario 700 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-6. In some cases, the UE115 may be configured with an overall system bandwidth (e.g., 20MHz, 100MHz, etc.). In some examples, the UE115 may be configured to communicate via a narrow band or fractional frequency band (e.g., a 5MHz fractional frequency band, a 10MHz fractional frequency band, a20 MHz fractional frequency band, etc.) within the overall system bandwidth. In some examples, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the overall system bandwidth.

For example, the UE115 may be configured to operate on partial bands of the same bandwidth, which may be located at different locations in the frequency domain, or partial bands of different bandwidths (e.g., 5MHz bandwidth, 10MHz bandwidth, 20MHz bandwidth, etc.). The UE115 may be dynamically configured to retune between partial bands of the same or different bandwidth. For example, fractional frequency bands 705, 710, 715, and 720 may have the same bandwidth (e.g., 5 MHz). Partial bands 725 and 730 may have the same bandwidth, which may be different from the other partial bands (e.g., 10 MHz). The UE115 may operate on one partial band (e.g., partial band 705), but may receive a resource grant and retune to a different partial band (e.g., partial band 710).

In some examples, the base station 105 and the UE115 may establish or reconfigure the connection using RRC messaging. The base station 105 may transmit an RRC message that may include a set of possible CSI-RS configurations. Each possible CSI-RS configuration in the set may include resource elements on which the UE115-a may obtain CSI-RS measurements. The CSI-RS configuration may include one CSI-RS configuration per partial band. For example, the RRC message may indicate one CSI-RS configuration for a partial band having a bandwidth of 5MHz, and a different CSI-RS configuration for a partial band having a bandwidth of 10MHz, and yet another CSI-RS configuration for a partial band having a bandwidth of 20 MHz. Alternatively, the CSI-RS configuration may include a plurality of CSI-RS configurations for each partial band. In some examples, the set of possible CSI-RS configurations may include a subset of CSI-RS configurations. In some examples, a possible CSI-RS configuration may correspond to a particular type of CSI-RS (e.g., periodic, aperiodic, or semi-persistent CSI-RS information). Additionally or alternatively, the set of possible CSI-RS configurations may be based on frequency locations within the total bandwidth, or fractional frequency bands within the total bandwidth.

For example, the set of CSI-RS configurations may indicate a first CSI-RS configuration a 1735 corresponding to a first bandwidth (e.g., 5MHz) and a second CSI-RS configuration a 2740 corresponding to the first bandwidth (e.g., 5 MHz). Additionally, the set of CSI-RS configurations may indicate a first CSI-RS configuration B1745 corresponding to a second bandwidth (e.g., 10MHz) and a second CSI-RS configuration B2750 corresponding to the second bandwidth (e.g., 10 MHz).

UE115 may operate on partial band 705. In such scenarios, the UE115 may utilize CSI-RS configuration a 1735 for CSI-RS measurements. However, the UE115 may receive a downlink grant from the base station 105, which may include DCI. The DCI may indicate a partial band retuning from partial band 705 to partial band 710. The UE115 may retune to the partial band 710 during the retuning gap 755. While operating on the partial band 710, the UE115 may determine that a portion of the CSI-RS configuration a 2740-a corresponds to the partial band 710 and may utilize resources of the CSI-RS configuration a 2740-a for CSI-RS measurements at the corresponding time. The UE115 may determine that the CSI-RS configuration a 2740-a corresponds to the partial band based on the RRC message only. Alternatively, the base station 105 may indicate in the DCI which CSI-RS configuration the UE115 should use when obtaining CSI-RS measurements.

The UE115 may receive additional downlink grants and may retune to the partial frequency band 715 in response to the grants. The UE115 may determine that a different portion of the CSI-RS configuration a 2740-a corresponds to the partial band 715 and may utilize resources of the CSI-RS configuration a 2740-b for CSI-RS measurements. The UE115 may determine that the CSI-RS configuration a 2740-b corresponds to the partial band 715 based on an RRC message alone or based on DCI triggering retuning from the partial band 710 to the partial band 715.

The UE115 may receive another downlink grant instructing a retuning from the partial band 715 to the partial band 725. Partial band 725 may have a different bandwidth than partial band 715. Fractional frequency band 725 is, for example, a 10MHz fractional frequency band. The UE115 may determine that a portion of CSI-RS configuration B1745 corresponds to the partial band 725 and may utilize the resources of CSI-RS configuration B1745 for CSI-RS measurements at corresponding times. However, when the UE115 receives another downlink grant, the UE115 may retune to the partial band 730, which may have the same bandwidth as the partial band 725. The UE115 may determine that at least a portion of the CSI-RS configuration B2750-B corresponds to the partial band 730 and may make CSI-RS measurements based thereon.

The UE115 may determine which CSI-RS configuration corresponds to the current partial baseband based on RRC messages alone or based on DCI that triggers retuning from the partial band 710 to the partial band 715. For example, CSI-RS configuration B2750-a may be the only CSI-RS configuration corresponding to partial band 730. In such examples, the UE115 may determine to utilize the CSI-RS configuration for measurements based only on RRC messages. However, in some cases, there may be multiple CSI-RS configurations applicable for a given fractional frequency band. In such a case, the base station 105 may include in the DCI a direction to retune to the partial band and an indication of which CSI-RS configuration corresponding to the partial band to use for CSI-RS measurements. In such examples, the UE115 may determine which CSI-RS configuration to utilize based on the DCI.

Fig. 8 illustrates an example of a CSI-RS configuration hierarchy 800 supporting CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the CSI-RS configuration settings 800 may implement aspects of the wireless communication system 100. In some cases, the configuration settings 800 may represent aspects of a technique performed by the UE115 or the base station 105 as described with reference to fig. 1-7. In some cases, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the system bandwidth. In such examples, the base station 105 may include the CSI measurement settings in an RRC message, which may include one or more sets of CSI-RS configurations.

The base station 105 may configure CSI report settings 805. The CSI reporting setup may include one or more sets of possible CSI-RS configurations. The CSI-RS configurations may be organized such that the UE115-a may select an appropriate CSI-RS configuration based on a variety of criteria including frequency of the partial band, bandwidth of the partial band, or time domain behavior.

For example, the CSI-RS configuration within CSI report setup 805 may include resource setup a810 for a first fractional frequency band and resource setup B815 for a second fractional frequency band. Resource setting a810 may include multiple CSI-RS configurations, including different sets of CSI-RS resources. For example, resource setting a810 may include CSI-RS resource set a 1820 and CSI-RS resource set a 2825, which may be options corresponding to the first fractional frequency band. Resource setting 815 may include CSI-RS resource set B1830 and CSI-RS resource set B2835, which may be options corresponding to the second fractional frequency band.

The base station 105 may transmit CSI measurement settings 840 to the UE115, which may be included in DCI or MAC CE signaling. For example, the base station 105 may include a resource grant corresponding to the first fractional frequency band in the DCI. The CSI measurement settings 840 may then indicate that the UE115 is to operate on the first fractional frequency band and therefore should utilize resource setting a 810. Further, UE115 may select one of CSI-RS resource set a 1820 or CSI-RS resource set a 2825 based on the narrowband location in the frequency domain. For example, the first fractional frequency band may be a 5MHz fractional frequency band. UE115 may select CSI-RS resource set a 1820 if the 5MHz partial band is located at a higher frequency range. Alternatively, if the 5MHz partial band is located at a lower frequency range, the UE115 may select CSI-RS resource set a 2825.

Fig. 9 illustrates an example of a CSI-RS configuration hierarchy 900 supporting CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, the CSI-RS configuration settings 900 may implement aspects of the wireless communication system 100. In some cases, the configuration settings 900 may represent aspects of a technique performed by a UE115 or a base station 105 as described with reference to fig. 1-8. In some cases, the base station 105 may dynamically configure the UE115 to operate on different fractional frequency bands within the system bandwidth. In such examples, the base station 105 may include the CSI measurement settings in an RRC message, which may include one or more sets of CSI-RS configurations.

The base station 105 may configure CSI report settings 905. The CSI reporting setup may include one or more sets of possible CSI-RS configurations. The CSI-RS configurations may be organized such that the UE115-a may select an appropriate CSI-RS configuration based on a variety of criteria including frequency of the partial band, bandwidth of the partial band, or time domain behavior.

For example, the CSI-RS configuration within CSI report settings 805 may include resource setting 1910 and resource setting 2. Resource setting a 910 may include multiple CSI-RS configurations, including different sets of CSI-RS resources. For example, resource setting 1910 may include CSI-RS resource set a 1920 for the first frequency band and CSI-RS resource set B1925 for the second frequency band. Resource setting 2915 may include a CSI-RS resource set a 2930 for the first frequency band and a CSI-RS resource set B2935 for the second frequency band.

The base station 105 may transmit CSI measurement settings 940 to the UE115, which may be included in DCI or MAC CE signaling. For example, the base station 105 may include a resource grant corresponding to the first fractional frequency band in the DCI. In some examples, resource setting 1910 may correspond to a higher portion of the frequency domain and resource setting 2915 may correspond to a lower portion of the frequency domain. The CSI measurement settings 940 may indicate that the UE115 is to operate on a partial band at a particular location in the frequency domain. For example, the UE115 may retune to a fractional frequency band corresponding to a higher portion of the frequency domain and may thus utilize the resource setting 1910.

Further, the UE115 may operate on a particular frequency band (such as a first frequency band). In such examples, UE115 may select one of CSI-RS resource set a 1920 or CSI-RS resource set B1925 based on which partial band has been assigned thereto. For example, the first fractional frequency band may be a 5MHz fractional frequency band. UE115 may determine that CSI-RS resource set a 1920 corresponds to the 5MHz partial band and may select a CSI-RS configuration based thereon. Similarly, if the DCI indicates that the UE115 should retune to the 10MHz partial band in the lower portion of the frequency domain, the UE115 may select resource setting 2 and may select CSI-RS resource set B2 for the second frequency band 935 if the second frequency band is a 10MHz frequency band within resource setting 2.

Fig. 10 illustrates an example of a process flow 1000 supporting a CSI-RS configuration for partial band retuning in accordance with various aspects of the present disclosure. In some examples, process flow 1000 may implement aspects of wireless communication system 100. Process flow 1000 may include a base station 105-b and a UE 115-b, which may be examples of a UE115 or base station 105 as described with reference to fig. 1-9 or may represent aspects of a technique performed by a UE115 or base station 105 as described with reference to fig. 1-9.

At 1005, the base station 105-b may transmit a message to a User Equipment (UE) indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth for the UE. For example, the message may be an RRC connection setup message or an equivalent message in response to an RRC connection request message or an equivalent message. Alternatively, the message may be an RRC connection reconfiguration message or an equivalent message. The base station 105-b may include information about the CSI-RS time domain behavior in an RRC message. For example, the base station 105-b may configure the CSI-RS transmission to be periodic or aperiodic. Alternatively, the base station 105-b may configure the UE 115-b to make aperiodic CSI-RS measurements, which may be dynamically triggered. For example, at 1010, the base station 105-b may transmit information regarding partial band retuning and aperiodic CSI-RS configuration with DCI. Further, the transmitted message may be an RRC message or a MAC layer message.

At 1010, the base station 105-b may transmit DCI to the UE, the DCI indicating a set of downlink resources associated with a first partial-band of the plurality of partial-bands. The DCI may be transmitted on a Physical Downlink Control Channel (PDCCH), and the set of downlink resources may be indicated in a downlink grant. The DCI may include explicit or implicit instructions to retune a receiver of the UE from the second partial band to the first partial band based on downlink resources indicated in the DCI. In some examples, the DCI may further include: an explicit or implicit indication of which of a set of possible CSI-RS configurations the UE 115-b may utilize in the DCI.

For example, the DCI may indicate to the UE 115-b that the UE 115-b is to retune from the first fractional frequency band to the second fractional frequency band. In some examples, the UE 115-b may have received a set of possible CSI-RS configurations at 1005, with one CSI-RS configuration corresponding to each frequency band. In such examples, the UE 115-b may determine the CSI-RS configuration simply by identifying the partial frequency band to which the UE 115-b will tune. Alternatively, the message received at 1005 may include multiple CSI-RS configurations for each partial band. In such examples, the DCI may include: an explicit indication of which of the possible CSI-RS configurations corresponding to the new partial band the UE 115-b should utilize. For example, the DCI may include a bitmap indicating one of the possible CSI-RS configurations. If the message received at 1005 indicates four possible CSI-RS configurations, the bitmap may include two bits indicating which of the four possibilities should be utilized by the UE 115-b.

Additionally or alternatively, the DCI may include characteristics based on which the UE 115-b should determine which CSI-RS configuration to use. The characteristics over which the UE 115-b may make its determination may include location in the frequency domain, and bandwidth of the partial band. For example, the DCI may indicate: if the UE 115-b is retuning to the first bandwidth, a particular CSI-RS is used if the bandwidth falls at a lower frequency in the frequency domain and a different CSI-RS is used if the bandwidth falls at a higher frequency in the frequency domain.

At 1015, the UE 115-b may select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on the DCI. UE 115-b may retune the receiver of the UE from the second partial-band to the first partial-band based at least in part on the received DCI. The UE 115-b may select the CSI-RS configuration based at least in part on periodic CSI-RS information, aperiodic CSI-RS information, or semi-persistent CSI-RS information in the message received at 1005.

In some examples, the set of possible CSI-RS configurations includes at least two subsets of the possible CSI-RS configurations corresponding to different CSI-RS time domain characteristics. At least one of the possible subsets of CSI-RS configurations may correspond to a periodic CSI-RS configuration, an aperiodic CSI-RS configuration, or a semi-persistent CSI-RS configuration. In some examples, UE 115-b may compare the time-domain CSI-RS configuration it received at 1005 with possible CSI-RS configurations and granted resources at 1010. Based on the granted resources (i.e., the partial band to which the UE 115-b may retune), the set of possible configurations, and the current timing, the UE 115-b may select a CSI-RS configuration. If the CSI-RS configuration is periodic, the UE 115-b may determine when the next periodic CSI-RS transmission will occur, and the corresponding CSI-RS configuration. If the CSI-RS is aperiodic, the UE 115-b may determine which CSI-RS configuration to select based on the indication included in the DCI. At 1020, the base station 105-b may perform CSI-RS transmission during the set of downlink resources according to the determined CSI-RS configuration.

At 1025, the UE 115-b may obtain CSI-RS measurements on the first fractional frequency band during the set of downlink resources using the selected first CSI-RS configuration. In some examples, at least one of the set of possible CSI-RS configurations corresponds to a Zero Power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero power (NZP) CSI-RS. At 1030, the UE 115-b may transmit a Channel State Information (CSI) report to the base station based at least in part on a CSI-RS measurement on the first partial band.

Fig. 11 shows a block diagram 1100 of a wireless device 1105 supporting Channel State Information (CSI) -RS configuration for partial band retuning in accordance with aspects of the present disclosure. The wireless device 1105 may be an example of aspects of a User Equipment (UE)115 as described herein. The wireless device 1105 may include a receiver 1110, a UE communications manager 1115, and a transmitter 1120. The wireless device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

Receiver 1110 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to CSI-RS configurations for partial band retuning, etc.). Information may be passed to other components of the device. The receiver 1110 may be an example of aspects of the transceiver 1435 described with reference to fig. 14. Receiver 1110 can utilize a single antenna or a set of antennas. The UE communications manager 1115 may be an example of aspects of the UE communications manager 1415 described with reference to fig. 14.

The UE communications manager 1115 and/or at least some of its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the UE communications manager 1115 and/or at least some of its various subcomponents may be performed by a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

The UE communications manager 1115 and/or at least some of its various subcomponents may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical devices at different physical locations. In some examples, the UE communications manager 1115 and/or at least some of its various subcomponents may be separate and distinct components in accordance with various aspects of the present disclosure. In other examples, the UE communications manager 1115 and/or at least some of its various subcomponents, in accordance with various aspects of the present disclosure, may be combined with one or more other hardware components (including, but not limited to, an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

The UE communications manager 1115 may receive a message from a base station indicating a set of possible CSI-RS configurations for each partial-band of a set of partial-bands within a total configured bandwidth of the UE, receive DCI from the base station indicating a set of downlink resources associated with a first partial-band of the set of partial-bands, select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial-band based on the DCI, and obtain CSI-RS measurements on the first partial-band during the set of downlink resources using the selected first CSI-RS configuration. The UE communications manager 1115 may also: the method generally includes receiving, from a base station, a CSI-RS configuration associated with a first partial band within a total configured bandwidth of a UE, receiving, from the base station, DCI indicating a set of downlink resources associated with a second partial band within the total configured bandwidth of the UE, and transmitting one of an error message or a partial CSI report to the base station based on a degree of overlap between the first partial band and the second partial band.

The transmitter 1120 may transmit signals generated by other components of the device. In some examples, the transmitter 1120 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1120 may be an example of aspects of the transceiver 1435 described with reference to fig. 14. Transmitter 1120 may utilize a single antenna or a set of antennas.

Fig. 12 shows a block diagram 1200 of a wireless device 1205 that supports CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The wireless device 1205 may be an example of aspects of the wireless device 1105 or the UE115 as described with reference to fig. 11. The wireless device 1205 may include a receiver 1210, a UE communication manager 1215, and a transmitter 1220. The wireless device 1205 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

Receiver 1210 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to CSI-RS configuration for partial band retuning, etc.). Information may be passed to other components of the device. The receiver 1210 may be an example of aspects of the transceiver 1435 described with reference to fig. 14. Receiver 1210 can utilize a single antenna or a set of antennas.

The UE communications manager 1215 may be an example of aspects of the UE communications manager 1415 described with reference to fig. 14. The UE communications manager 1215 may further include: a configuration component 1225, a DCI component 1230, a selection component 1235, a measurement component 1240, and an overlap determination component 1245.

Configuration component 1225 can receive a message from the base station indicating a set of possible CSI-RS configurations for each partial band of the set of partial bands within the total configured bandwidth of the UE, and receive a CSI-RS configuration from the base station associated with a first partial band within the total configured bandwidth of the UE. In some cases, the received message is a Radio Resource Control (RRC) message. In some cases, the received message is a Media Access Control (MAC) layer message. In some cases, at least one of the set of possible CSI-RS configurations corresponds to a Zero Power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero power (NZP) CSI-RS. In some cases, the set of possible CSI-RS configurations includes at least two subsets of the possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

DCI component 1230 may receive DCI from a base station indicating a set of downlink resources associated with a first partial band of a set of partial bands and DCI from a base station indicating a set of downlink resources associated with a second partial band within a total configured bandwidth of a UE.

Selection component 1235 may select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based on the DCI, select one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first partial band based on periodic CSI-RS information in the received message, and select one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first partial band based on semi-persistent CSI-RS information in the received message. In some cases, selecting the CSI-RS configuration includes: an indication of a first CSI-RS configuration is received in DCI. Measurement component 1240 can obtain CSI-RS measurements over the first fractional frequency band during the set of downlink resources using the selected first CSI-RS configuration.

Overlap determining component 1245 can transmit one of an error message or a partial CSI report to the base station based on a degree of overlap between the first partial band and the second partial band, determine that the first partial band does not overlap the second partial band, transmit the error message based on the determination, determine a portion of the first partial band that overlaps the second partial band, and obtain CSI-RS measurements over the portion of the first partial band that overlaps the second partial band.

Transmitter 1220 may transmit signals generated by other components of the device. In some examples, the transmitter 1220 may be co-located with the receiver 1210 in a transceiver module. For example, the transmitter 1220 may be an example of aspects of the transceiver 1435 described with reference to fig. 14. Transmitter 1220 may utilize a single antenna or a set of antennas.

Fig. 13 illustrates a block diagram 1300 of a UE communications manager 1315 supporting CSI-RS configuration for partial band retuning in accordance with aspects of the disclosure. The UE communications manager 1315 may be an example of aspects of the UE communications manager 1115, the UE communications manager 1215, or the UE communications manager 1415 described with reference to fig. 11, 12 and 14. The UE communication manager 1315 may further include: a configuration component 1320, a DCI component 1325, a selection component 1330, a measurement component 1335, an overlap determination component 1340, a retuning component 1345, and a reporting component 1350. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

Configuration component 1320 can receive a message from a base station indicating a set of possible CSI-RS configurations for each partial band of a set of partial bands within a total configured bandwidth of a UE, and receive a CSI-RS configuration from the base station associated with a first partial band within the total configured bandwidth of the UE. In some cases, the received message is an RRC message. In some cases, the received message is a MAC layer message. In some cases, at least one of the set of possible CSI-RS configurations corresponds to a Zero Power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero power (NZP) CSI-RS. In some cases, the set of possible CSI-RS configurations includes at least two subsets of the possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

DCI component 1325 may receive DCI from a base station indicating a set of downlink resources associated with a first partial band of a set of partial bands and DCI from the base station indicating a set of downlink resources associated with a second partial band within a total configured bandwidth of a UE.

Selection component 1330 may select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based on the DCI, select one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first partial band based on periodic CSI-RS information in the received message, and select one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first partial band based on semi-persistent CSI-RS information in the received message. In some cases, selecting the CSI-RS configuration includes: an indication of a first CSI-RS configuration is received in DCI. Measurement component 1335 may obtain CSI-RS measurements on the first fractional frequency band during the set of downlink resources using the selected first CSI-RS configuration.

Overlap determining component 1340 may transmit one of an error message or a partial CSI report to the base station based on a degree of overlap between the first partial band and the second partial band, determine that the first partial band and the second partial band do not overlap, transmit the error message based on the determination, determine a portion of the first partial band that overlaps the second partial band, and obtain CSI-RS measurements over the portion of the first partial band that overlaps the second partial band.

Retuning component 1345 may retune the receiver of the UE from the second fractional frequency band to the first fractional frequency band based on the received DCI. Reporting component 1350 can transmit a CSI report to the base station based on the CSI-RS measurements on the first fractional frequency band.

Fig. 14 shows a diagram of a system 1400 including a device 1405 supporting a CSI-RS configuration for partial band retuning, in accordance with aspects of the present disclosure. Device 1405 may be an example of or include components of wireless device 1105, wireless device 1205, or UE115 as described above (e.g., with reference to fig. 11 and 12). The device 1405 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a UE communications manager 1415, a processor 1420, memory 1425, software 1430, a transceiver 1435, an antenna 1440, and an I/O controller 1445. These components may be in electronic communication via one or more buses, such as bus 1410. The device 1405 may communicate wirelessly with one or more base stations 105.

Processor 1420 may include intelligent hardware devices (e.g., general processor, DSP, Central Processing Unit (CPU), microcontroller, ASIC, FPGA, programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1420 may be configured to operate the memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1420. Processor 1420 may be configured to execute computer-readable instructions stored in memory to perform various functions (e.g., support functions or tasks for CSI-RS configuration for partial band retuning).

The memory 1425 can include Random Access Memory (RAM) and read-only memory (ROM). The memory 1425 may store computer-readable, computer-executable software 1430 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 1425 may contain, among other things, the basic input/output system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

The software 1430 may include code for implementing aspects of the disclosure, including code for supporting CSI-RS configuration for partial band retuning. Software 1430 may be stored in a non-transitory computer readable medium, such as system memory or other memory. In some cases, the software 1430 may not be directly executable by a processor, but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

The transceiver 1435 may communicate bi-directionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1435 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1435 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, as well as to demodulate packets received from the antenna.

In some cases, the wireless device may include a single antenna 1440. However, in some cases, the device may have more than one antenna 1440, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

I/O controller 1445 may manage input and output signals for device 1405. I/O controller 1445 may also manage peripheral devices that are not integrated into device 1405. In some cases, I/O controller 1445 may represent a physical connection or port to an external peripheral device. In some cases, I/O controller 1445 may utilize an operating system, such as Or another known operating system. In other cases, I/O controller 1445 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I/O controller 1445 may be implemented as part of a processor. In some cases, a user may interact with device 1405 via I/O controller 1445 or via hardware components controlled by I/O controller 1445.

Fig. 15 shows a block diagram 1500 of a wireless device 1505 that supports a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The wireless device 1505 may be an example of aspects of the base station 105 as described herein. The wireless device 1505 may include a receiver 1510, a base station communications manager 1515, and a transmitter 1520. The wireless device 1505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

The receiver 1510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to CSI-RS configuration for partial band retuning, etc.). Information may be passed to other components of the device. The receiver 1510 may be an example of aspects of a transceiver 1835 described with reference to fig. 18. The receiver 1510 may utilize a single antenna or a set of antennas. The base station communications manager 1515 may be an example of aspects of the base station communications manager 1815 described with reference to fig. 18.

The base station communications manager 1515 and/or at least some of its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the base station communications manager 1515 and/or at least some of its various subcomponents may be performed by a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure. The base station communications manager 1515 and/or at least some of its various subcomponents may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical devices at different physical locations. In some examples, the base station communications manager 1515 and/or at least some of its various subcomponents may be separate and distinct components in accordance with various aspects of the present disclosure. In other examples, the base station communications manager 1515 and/or at least some of its various subcomponents, in accordance with various aspects of the present disclosure, may be combined with one or more other hardware components (including, but not limited to, an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

The base station communications manager 1515 may transmit a message to the UE indicating a set of possible CSI-RS configurations for each of a set of partial bands within a total configured bandwidth for the UE, transmit DCI to the UE indicating a set of downlink resources associated with a first partial band of the set of partial bands, select a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based on the set of downlink resources, and perform CSI-RS transmission during the set of downlink resources according to the determined CSI-RS configuration.

The transmitter 1520 may transmit signals generated by other components of the apparatus. In some examples, the transmitter 1520 may be co-located with the receiver 1510 in a transceiver module. For example, the transmitter 1520 may be an example of aspects of the transceiver 1835 described with reference to fig. 18. Transmitter 1520 may utilize a single antenna or a set of antennas.

Fig. 16 shows a block diagram 1600 of a wireless device 1605 supporting a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The wireless device 1605 may be an example of aspects of the wireless device 1505 or the base station 105 described with reference to fig. 15. Wireless device 1605 may include a receiver 1610, a base station communications manager 1615, and a transmitter 1620. The wireless device 1605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

Receiver 1610 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to CSI-RS configuration for partial band retuning, etc.). Information may be passed to other components of the device. The receiver 1610 may be an example of aspects of a transceiver 1835 described with reference to fig. 18. Receiver 1610 can utilize a single antenna or a set of antennas.

The base station communications manager 1615 may be an example of aspects of the base station communications manager 1815 described with reference to fig. 18. Base station communications manager 1615 may also include configuration component 1625, DCI component 1630, selection component 1635, and CSI-RS component 1640.

Configuration component 1625 can transmit a message to the UE indicating a set of possible CSI-RS configurations for each of the set of partial bands within the total configuration bandwidth of the UE. In some cases, the transmitted message is a MAC layer message. In some cases, the set of possible CSI-RS configurations includes at least two subsets of the possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

DCI component 1630 may transmit DCI to the UE indicating a set of downlink resources associated with a first partial band of the set of partial bands.

Selection component 1635 may select a CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based on the set of downlink resources and select a CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based on periodic CSI-RS information in the transmitted message. In some cases, the transmitted message is an RRC message. In some cases, selecting the CSI-RS configuration includes: transmitting an indication of a first CSI-RS configuration in the DCI.

The CSI-RS component 1640 may perform CSI-RS transmission during the set of downlink resources according to the determined CSI-RS configuration, select a CSI-RS configuration from a set of possible CSI-RS configurations for the first fractional frequency band based on semi-persistent CSI-RS information in the transmitted message, and receive a CSI report from the UE based on the performed CSI-RS transmission according to the determined CSI-RS configuration. In some cases, at least one of the set of possible CSI-RS configurations corresponds to a Zero Power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero power (NZP) CSI-RS.

Transmitter 1620 may transmit signals generated by other components of the device. In some examples, the transmitter 1620 may be co-located with the receiver 1610 in a transceiver module. For example, the transmitter 1620 may be an example of aspects of a transceiver 1835 described with reference to fig. 18. Transmitter 1620 may utilize a single antenna or a set of antennas.

Fig. 17 shows a block diagram 1700 of a base station communications manager 1715 that supports a CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The base station communications manager 1715 may be an example of aspects of the base station communications manager 1815 described with reference to fig. 15, 16, and 18. Base station communications manager 1715 may include a configuration component 1720, a DCI component 1725, a selection component 1730, a CSI-RS component 1735, and a retuning component 1740. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

Configuration component 1720 may transmit a message to the UE indicating a set of possible CSI-RS configurations for each partial band of the set of partial bands within the total configuration bandwidth of the UE. In some cases, the transmitted message is a MAC layer message. In some cases, the set of possible CSI-RS configurations includes at least two subsets of the possible CSI-RS configurations that correspond to different CSI-RS time-domain characteristics. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a periodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to an aperiodic CSI-RS configuration. In some cases, at least one of the possible subsets of CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration. DCI component 1725 may transmit DCI to a UE indicating a set of downlink resources associated with a first partial band of a set of partial bands.

Selection component 1730 can select a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based on the set of downlink resources and select one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first partial band based on periodic CSI-RS information in the transmitted message. In some cases, the transmitted message is an RRC message. In some cases, selecting the CSI-RS configuration includes: transmitting an indication of a first CSI-RS configuration in the DCI.

CSI-RS component 1735 may perform CSI-RS transmission during the set of downlink resources in accordance with the determined CSI-RS configuration, select a CSI-RS configuration from a set of possible CSI-RS configurations for the first partial band based on semi-persistent CSI-RS information in the transmitted message, and receive a CSI report from the UE in accordance with the determined CSI-RS configuration based on the performed CSI-RS transmission. In some cases, at least one of the set of possible CSI-RS configurations corresponds to a Zero Power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero power (NZP) CSI-RS. Retuning component 1740 may transmit instructions to retune a receiver of the UE from the second partial band to the first partial band based via DCI.

Fig. 18 shows a diagram of a system 1800 including a device 1805 that supports a CSI-RS configuration for partial band retuning, in accordance with aspects of the present disclosure. The device 1805 may be an example of or include components of a base station 105 as described above (e.g., with reference to fig. 1). The device 1805 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a base station communications manager 1815, a processor 1820, memory 1825, software 1830, a transceiver 1835, an antenna 1840, a network communications manager 1845, and an inter-station communications manager 1850. These components may be in electronic communication via one or more buses, such as bus 1810. The device 1805 may be in wireless communication with one or more UEs 115.

The processor 1820 can include intelligent hardware devices (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1820 can be configured to operate a memory array using a memory controller. In other cases, the memory controller can be integrated into the processor 1820. The processor 1820 may be configured to execute computer-readable instructions stored in the memory to perform various functions (e.g., to support functions or tasks of a CSI-RS configuration for partial band retuning).

Memory 1825 may include RAM and ROM. The memory 1825 may store computer-readable, computer-executable software 1830 comprising instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 1825 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

The software 1830 may include code for implementing aspects of the present disclosure, including code for supporting CSI-RS configuration for partial band retuning. The software 1830 may be stored in a non-transitory computer-readable medium, such as a system memory or other memory. In some cases, the software 1830 may not be directly executable by a processor, but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

The transceiver 1835 may communicate bi-directionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1835 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1835 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and to demodulate packets received from the antenna. In some cases, the wireless device may include a single antenna 1840. However, in some cases, the device may have more than one antenna 1840, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The network communication manager 1845 may manage communication with the core network (e.g., via one or more wired backhaul links). For example, the network communication manager 1845 may manage the communication of data communications by a client device (such as one or more UEs 115).

The inter-station communication manager 1850 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with the UE115 in cooperation with the other base stations 105. For example, the inter-station communication manager 1850 may coordinate scheduling of transmissions to the UEs 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-station communication manager 1850 may provide an X2 interface within Long Term Evolution (LTE)/LTE-a wireless communication network technology to provide communication between base stations 105.

Fig. 19 shows a flow diagram illustrating a method 1900 for CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The operations of the method 1900 may be implemented by the UE115 or components thereof as described herein. For example, the operations of method 1900 may be performed by a UE communications manager as described with reference to fig. 11-14. In some examples, the UE115 may execute a set of codes to control the functional elements of the apparatus to perform the functions described below. Additionally or alternatively, the UE115 may use dedicated hardware to perform aspects of the functions described below.

At block 1905, the UE115 may receive a message from the base station indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE. The operations of block 1905 may be performed in accordance with the methods described herein. In some examples, aspects of the operations of block 1905 may be performed by a configuration component as described with reference to fig. 11-14.

At block 1910, the UE115 may receive DCI from a base station, the DCI indicating a set of downlink resources associated with a first fractional frequency band of a plurality of fractional frequency bands. The operations of block 1910 may be performed according to the methods described herein. In certain examples, aspects of the operations of block 1910 may be performed by the DCI component as described with reference to fig. 11-14.

At block 1915, the UE115 may select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial-band based at least in part on the DCI. The operations of block 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of block 1915 may be performed by a selection component as described with reference to fig. 11-14.

At block 1920, the UE115 may obtain CSI-RS measurements on the first fractional frequency band during the set of downlink resources using the selected first CSI-RS configuration. The operations of block 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of block 1920 may be performed by the measurement component described with reference to fig. 11-14.

Fig. 20 shows a flow diagram illustrating a method 2000 for CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The operations of method 2000 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of method 2000 may be performed by a base station communications manager as described with reference to fig. 15-18. In some examples, the base station 105 may execute sets of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform various aspects of the functions described below using dedicated hardware.

At block 2005, the base station 105 may transmit a message to a User Equipment (UE) indicating a set of possible CSI-RS configurations for each of a plurality of partial bands within a total configured bandwidth of the UE. The operations of block 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of block 2005 may be performed by a configuration component as described with reference to fig. 15-18.

At block 2010, the base station 105 may transmit DCI to the UE, the DCI indicating a set of downlink resources associated with a first partial-band of the plurality of partial-bands. The operations of block 2010 may be performed according to the methods described herein. In certain examples, aspects of the operations of block 2010 may be performed by the DCI component as described with reference to fig. 15-18.

At block 2015, the base station 105 may select a CSI-RS configuration from a set of possible CSI-RS configurations for the first partial band based at least in part on the set of downlink resources. The operations of block 2015 may be performed according to methods described herein. In some examples, aspects of the operations of block 2015 may be performed by a selection component as described with reference to fig. 15-18.

At block 2020, the base station 105 may perform CSI-RS transmission during the set of downlink resources according to the determined CSI-RS configuration. The operations of block 2020 may be performed in accordance with the methods described herein. In certain examples, aspects of the operations of block 2020 may be performed by CSI-RS components as described with reference to fig. 15 through 18.

Fig. 21 shows a flowchart illustrating a method 2100 for CSI-RS configuration for partial band retuning in accordance with aspects of the present disclosure. The operations of method 2100 may be implemented by a UE115 or components thereof as described herein. For example, the operations of method 2100 may be performed by a UE communications manager as described with reference to fig. 11 through 14. In some examples, the UE115 may execute a set of codes to control the functional elements of the apparatus to perform the functions described below. Additionally or alternatively, the UE115 may use dedicated hardware to perform aspects of the functions described below.

At block 2105, the UE115 may receive, from the base station, a CSI-RS configuration associated with a first fractional frequency band within a total configuration bandwidth of the UE. The operations of block 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of block 2105 may be performed by a configuration component as described with reference to fig. 11-14.

At block 2110, the UE115 may receive DCI from the base station indicating a set of downlink resources associated with the second fractional frequency band within the UE's total configured bandwidth. The operations of block 2110 may be performed in accordance with the methods described herein. In certain examples, aspects of the operations of block 2110 may be performed by the DCI component as described with reference to fig. 11-14.

At block 2115, the UE115 may transmit one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first partial band and the second partial band. The operations of block 2115 may be performed according to the methods described herein. In some examples, aspects of the operations of block 2115 may be performed by an overlap determination component as described with reference to fig. 11-14.

It should be noted that the above method describes possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. In some examples, aspects of two or more of the methods 1900, 2000, or 2100 described with reference to fig. 19, 20, or 21 may be combined. It should be noted that methods 1900, 2000, and 2100 are merely example implementations, and the operations of methods 1900, 2000, or 2100 may be rearranged or otherwise modified such that other implementations are possible. .

The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and others. The terms "system" and "network" are often used interchangeably. Code Division Multiple Access (CDMA) systems may implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and the like. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. The IS-2000 version may often be referred to as CDMA20001X, 1X, etc. IS-856(TIA-856) IS often referred to as CDMA20001xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (wcdma) and other CDMA variants. TDMA systems may implement radio technologies such as global system for mobile communications (GSM).

The OFDMA system may implement radio technologies such as Ultra Mobile Broadband (UMB), evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE)802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are UMTS releases using E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, NR, and GSM are described in documents from an organization named "third Generation partnership project" (3 GPP). CDMA2000 and UMB are described in documents from an organization named "third generation partnership project 2" (3GPP 2). The techniques described herein may be used for both the above-mentioned systems and radio technologies, as well as for other systems and radio technologies. Although aspects of the LTE or NR system may be described for example purposes, and LTE or NR terminology may be used in much of the description above, the techniques described herein may also be applied to applications other than LTE or NR applications.

In LTE/LTE-a networks, including such networks described herein, the term evolved node B (eNB) may be used generically to describe a base station. One or more wireless communication systems described herein may include heterogeneous LTE/LTE-a or NR networks in which different types of enbs provide coverage for various geographic regions. For example, each eNB, next generation node B (gNB), or base station may provide communication coverage for a macro cell, a small cell, or other type of cell. Depending on the context, the term "cell" may be used to describe a base station, a carrier or component carrier associated with a base station, or a geographic coverage area (e.g., sector, etc.) of a carrier or base station.

A base station may include, or may be referred to by those skilled in the art as, a base transceiver station, a radio base station, an access point, a radio transceiver, a node B, an evolved node B (eNB), a gNB, a home node B, a home evolved node B, or some other suitable terminology. The geographic coverage area of a base station may be partitioned into sectors that form only a portion of the coverage area. One or several wireless communication systems described herein may include different types of base stations (e.g., macro or small cell base stations). The UEs described herein may be capable of communicating with various types of base stations and network equipment, including macro enbs, small cell enbs, gbbs, relay base stations, and so forth. There may be overlapping geographic coverage areas of different technologies.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. Small cells are low power base stations that may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency bands as macro cells as compared to macro cells. According to various examples, a small cell may include a picocell, a femtocell, and a microcell. Picocells, for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femtocell may also cover a smaller geographic area (e.g., a residence) and may be provided access restricted by UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of users in the residence, etc.). The eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells (e.g., component carriers).

One or more of the wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, each base station may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, each base station may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operations.

The downlink transmissions described herein may also be referred to as forward link transmissions, while the uplink transmissions may also be referred to as reverse link transmissions. Each of the communication links described herein, including, for example, the wireless communication systems 100 and 200 of fig. 1 and 2, may include one or more carriers, where each carrier may be a signal (e.g., a waveform signal of a different frequency) made up of a plurality of subcarriers.

The illustrations set forth herein in connection with the figures describe example configurations and are not intended to represent all examples that may be implemented or fall within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," and does not mean "preferred" or "advantageous over other examples. The detailed description includes specific details to provide an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

In the drawings, similar components or features may have the same reference numerals. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and the following claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. Features that implement functions may also be physically located at various locations, including being distributed such that portions of functions are implemented at different physical locations. As used herein, including in the claims, the term "and/or" as used in a listing of two or more items means that any one of the listed items can be employed alone, or any combination of two or more of the listed items can be employed. For example, if a composition is described as comprising component A, B and/or C, the composition may comprise only a; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B and C. Also, as used herein, including in the claims, "or" as used in a list of items (e.g., a list of items accompanied by a phrase such as "at least one of" or "one or more of") indicates an inclusive list such that, for example, a phrase referring to at least one of the list of items "refers to any combination of such items, including single members. By way of example, "at least one of A, B or C" is intended to encompass: A. b, C, A-B, A-C, B-C, and a-B-C, as well as any combination of multiple identical elements (e.g., a-A, A-a-A, A-a-B, A-a-C, A-B-B, A-C-C, B-B, B-B-B, B-B-C, C-C and C-C, or any other ordering of A, B and C).

Also, as used herein, the phrase "based on" should not be read as referring to a closed condition set. For example, an exemplary step described as "based on condition a" may be based on both condition a and condition B without departing from the scope of the present disclosure. In other words, the phrase "based on," as used herein, should be interpreted in the same manner as the phrase "based, at least in part, on.

Computer-readable media includes both non-transitory computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can comprise RAM, ROM, electrically erasable programmable read-only memory (EEPROM), Compact Disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk (disk) and disc (disc), as used herein, includes CD, laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication, comprising:

receiving, from a base station, a message indicating a set of possible channel state information reference signal (CSI-RS) configurations for each of a plurality of partial frequency bands within a total configuration bandwidth of a UE;

receiving Downlink Control Information (DCI) from the base station, the DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands;

selecting a first CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on the DCI; and

obtaining CSI-RS measurements on the first fractional frequency band during the set of downlink resources using the selected first CSI-RS configuration.

2. The method of claim 1, further comprising:

retuning a receiver of the UE from a second fractional frequency band to the first fractional frequency band based at least in part on the received DCI.

3. The method of any one of claim 1 or claim 2, further comprising:

selecting one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on periodic CSI-RS information in the received message.

4. The method of any of claims 1 to 3, wherein the received message is a Radio Resource Control (RRC) message.

5. The method of any one of claim 1 or claim 2, further comprising:

selecting one or more CSI-RS configurations from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on semi-persistent CSI-RS information in the received message.

6. The method of claim 1, wherein the received message is a Media Access Control (MAC) layer message.

7. The method of any one of claim 5 or claim 6, wherein selecting the CSI-RS configuration comprises:

receiving an indication of the first CSI-RS configuration in the DCI.

8. The method of any one of claim 6 or claim 7, further comprising:

transmitting a Channel State Information (CSI) report to the base station based at least in part on the CSI-RS measurement on the first partial band.

9. The method according to any of claims 6 to 8, wherein at least one of the set of possible CSI-RS configurations corresponds to a zero-power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero-power (NZP) CSI-RS.

10. The method of claim 1, wherein the set of possible CSI-RS configurations comprises at least two subsets of possible CSI-RS configurations corresponding to different CSI-RS time domain characteristics.

11. The method of claim 10, wherein at least one of the subset of possible CSI-RS configurations corresponds to a periodic CSI-RS configuration.

12. The method of any one of claim 10 or claim 11, wherein at least one of the subset of possible CSI-RS configurations corresponds to an aperiodic CSI-RS configuration.

13. The method of claims 10 to 12, wherein at least one of the subset of possible CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

14. A method for wireless communication, comprising:

transmitting, to a User Equipment (UE), a message indicating a set of possible channel state information reference message (CSI-RS) configurations for each of a plurality of partial bands within a total configured bandwidth of the UE;

transmitting Downlink Control Information (DCI) to the UE, the DCI indicating a set of downlink resources associated with a first partial band of the plurality of partial bands;

selecting a CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on the set of downlink resources; and

performing CSI-RS transmission during the set of downlink resources according to the determined CSI-RS configuration.

15. The method of claim 14, further comprising:

transmitting instructions to retune a receiver of the UE from a second partial band to the first partial band based via the DCI.

16. The method of at least one of claim 14 or claim 15, further comprising:

selecting a CSI-RS configuration from the set of possible CSI-RS configurations for the first fractional frequency band based at least in part on periodic CSI-RS information in the transmitted message.

17. The method of any of claims 14 to 16, wherein the transmitted message is a Radio Resource Control (RRC) message.

18. The method of any of claims 14 to 17, further comprising:

selecting a CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based at least in part on semi-persistent CSI-RS information in the transmitted message.

19. The method of any of claims 14 to 18, wherein the transmitted message is a Medium Access Control (MAC) layer message.

20. The method of claim 14, wherein selecting the CSI-RS configuration comprises:

transmitting an indication of the first CSI-RS configuration in the DCI.

21. The method of claim 14, further comprising:

receiving a Channel State Information (CSI) report from the UE according to the determined CSI-RS configuration based at least in part on the performed CSI-RS transmission.

22. The method of claim 14, wherein at least one of the set of possible CSI-RS configurations corresponds to a zero-power (ZP) CSI-RS, and at least one of the set of possible CSI-RS configurations corresponds to a non-zero-power (NZP) CSI-RS.

23. The method of claim 14, wherein the set of possible CSI-RS configurations comprises at least two subsets of possible CSI-RS configurations corresponding to different CSI-RS time domain characteristics.

24. The method of claim 23, wherein at least one of the subset of possible CSI-RS configurations corresponds to a periodic CSI-RS configuration.

25. The method of any one of claim 23 or claim 24, wherein at least one of the subset of possible CSI-RS configurations corresponds to an aperiodic CSI-RS configuration.

26. The method of any one of claims 23 to 25, wherein at least one of the subset of possible CSI-RS configurations corresponds to a semi-persistent CSI-RS configuration.

27. A method for wireless communication, comprising:

receiving, from a base station, a CSI-RS configuration associated with a first fractional frequency band within a total configuration bandwidth of a UE;

receiving Downlink Control Information (DCI) from the base station, the DCI indicating a set of downlink resources associated with a second fractional frequency band within the total configured bandwidth of the UE; and

transmitting one of an error message or a partial CSI report to the base station based at least in part on a degree of overlap between the first partial band and the second partial band.

28. The method of claim 27, further comprising:

determining that the first fractional frequency band does not overlap the second fractional frequency band; and

transmitting the error message based at least in part on the determination.

29. The method of claim 27, further comprising:

determining a portion of the first fractional frequency band that overlaps the second fractional frequency band; and

obtaining CSI-RS measurements on the portion of the first fractional frequency band that overlaps the second fractional frequency band.

30. An apparatus for wireless communication, comprising:

a processor;

a memory in electronic communication with the processor; and

instructions stored in the memory and operable when executed by the processor to cause the apparatus to: